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<head>
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    <title>Document</title>
</head>
<body>
    <script>
        var arr = [
            {
                data: [
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 6457 },
                    { name: 'zhangsan', value: 1324 },
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                    { name: 'zhangsan', value: 75678 },
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                data: [
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 4577 },
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 64572 },
                    { name: 'zhangsan', value: 1324 },
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                data: [
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 1249875 },
                    { name: 'zhangsan', value: 1324 },
                    { name: 'zhangsan', value: 985904385 },
                    { name: 'zhangsan', value: 1324 },
                ],
            },
        ];

        function getMax (arr) {
            var max = -Infinity;
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                    if (subItem.value > max) {
                        max = subItem.value;
                    }
                }
            }
            return max;
        }

        console.log( getMax(arr) ); 


    </script>
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